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sgjfrods 12-12-2012 02:34 PM

Can you run your engine without a water intake

I have my boat out of the water and will do for a year or two, whilst i do work on it.
I would like to run the engine periodically, however it is a pain to get water to the water intake for various reasons, as even a large bucket only lasts a minute.
I believe the water intake takes water out of the sea/lake passes it through a heat ex-changer which cools the internal engine water with the antifreeze in which then pumps around the engine.

My question is, is it possible to run the engine for just a couple of minutes (as that's all i need to do, to keep things ticking over) without it sucking any water from the water intake and just use the internal engine coolant for this short period of time, or will it do damage to the impella or worse being ran dry?

Thanks very much for any help.

RobGallagher 12-12-2012 02:38 PM

Re: Can you run your engine without a water intake
I think you would be better of pickling it then running it on the hard for short periods under no load over a span of a couple of years.

capttb 12-12-2012 02:52 PM

Re: Can you run your engine without a water intake
The raw water impellor will self destruct within minutes if run dry, as most of us have learned the hard way, and the pieces clog the heat exchanger. If you remove it you could probably run for a few minutes but as Rob said, you wouldn't be doing it a favor.

pyewackette 12-12-2012 04:34 PM

Re: Can you run your engine without a water intake
I have a valve that diverts my engine water intake from the through hull to a hose that goes to the bilge. I do this as a back up dewatering solution in case my bilge pump fails and I have water coming in. When my boat is put on the hard, (or I have even used it to winterize the engine), I fill up the bilge with water and run the engine. Works great, but I have only used it that way out of the water for a couple of months, not years. The load issue might be a concern, and the suggestion of pickling seems reasonable. .

klem 12-12-2012 05:48 PM

Re: Can you run your engine without a water intake
As mentioned, the only issue with a short run will be the impeller. You can easily pull the impeller and run the engine for a short period of time. Depending on the seal type on your raw water pump, you may get marginally shorter life out of it but it is a very small concern.

The other way you can do it is to run a continuous loop system where you feed the exhaust water back in to your bucket. The concern here is that you don't want to melt the bucket.

With either of these methods, the key is that you can only do short runs. If you run for too long, things are going to get hot and there are a few risks. One risk is that you start creating steam in your cooling passages which is bad as steam is 600 times less dense than the water it replaces. If you are at the point of creating steam, you are also getting to the point where you damage the engine from overheating. Another major concern would be that your exhaust hose will be hotter if it normally has water going through it.

I think that you first need to justify why you want to run the engine regularly. A properly laid up engine will be fine for 2 years.

Faster 12-12-2012 06:29 PM

Re: Can you run your engine without a water intake
There is a second concern running a FWC engine with the RW circuit dry.. the water lift and the rest of the exhaust system are intended to be cooled by the exhausted RWC.. running 'dry' in that respect could damage or overheat certain components of the exhaust system - esp 'plastic' water lift mufflers.

I'd go with the big bucket, a garden hose and another RW intake hose if you can't somehow connect to your through hull intake.

sgjfrods 12-12-2012 07:17 PM

Re: Can you run your engine without a water intake
Okay, I didn't consider the hot exhaust option.

The reason why I would want to run the engine is that I have recently got the boat and wanted to gain some confidence in that the engine is a regular starter and that the glow plug starter is all working etc.

I will go with big bucket, and keeping the starting to a minimum.

Then will just put some anti freeze in the engine and leave it.

Are there any other tips for laying up the engine for a relatively long period of time?

Thanks for all your help!

jrd22 12-12-2012 09:04 PM

Re: Can you run your engine without a water intake
Just open up your raw water strainer, with the seacock closed, and run a hose into it while running the engine. Do NOT hook up a garden hose directly to the hose that feeds the raw water pump, you don't want pressure to the suction side. Your exhaust will flow out the through hull like normal.
Running the engine once a month is a very good idea.

chucklesR 12-12-2012 09:06 PM

Re: Can you run your engine without a water intake
Standard winterization and or layup schedule as per the operator's manual is what you should stick to.

As to confidence in the engine- HA! Every time you turn the key is different. It's like the say for selling stocks and bonds, past performance is no guarantee of future performance.

Seriously, lay it up, wait, and when you recommission it then the confidence begins to build. Clean air, clean fuel, and good compression- that's all it takes to make to run.

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